Investigation of drought characteristics in different temporal and spatial scales: A case study in the Mediterranean region

In 1988-1995 Greece experienced a drought, one of the most extended (both in space and time) and intense since the beginning of hydro-meteorological instrumental measurements. The aim of this study is to describe the phenomenon in different temporal and spatial scales in order to (a) identify possible links with Mediterranean/global climatic regime and (b) to demonstrate the role of the marginal distribution and the autocorrelation function in estimating the return period of the drought and its impact. Three spatial scales were examined: the local scale (regions of Peloponnese in the southern and Macedonia in the northern part of Greece; ~2x2° each), the national scale (~8x8°) and the Mediterranean scale (~15x45°). In the time domain the monthly, annual and inter-annual time steps were taken, while the time horizon is that of the instrumental record as well as a broader time window obtained by introducing qualitative evidence from paleoclimatic studies. Our findings show both strong temporal variability and spatial heterogeneity, which imply enhanced uncertainty.